Common squid
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Common squid ( Sepia officinalis ) |
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| Scientific name | ||||||||||||
| Sepia officinalis | ||||||||||||
| Linnaeus , 1758 |
The common octopus ( Sepia officinalis ) is a species of cephalopods that belongs to the ten-armed octopus . It occurs on the coasts of Western Europe, North Africa, the Mediterranean and the North Sea. The common squid grows to 49 cm long and weighs up to four kilograms.
anatomy
Eight arms are arranged around the mouth, two more are hidden in coat pockets and only come out to catch prey. The long tentacles take the prey and give it to the shorter arms. The common octopus has lenticular eyes that can see about as well as vertebrates . In order to camouflage itself, the common squid changes color through skin cells, in which different colored pigments can be pulled apart by muscle fibers, whereby many colors can be represented.
They have a "back bone" called Schulp , which serves as a float.
Fishing behavior
There are two types of prey in common squid. On the one hand the so-called tentacle shot and on the other hand the jump for prey. Which of these is used depends on the type and size of the prey. The tentacle shot is only used for smaller crabs, crabs, shrimps and fish. The common squid first stands in a position from which it can see the prey well, then it spreads the short tentacles to the side and the two long tentacles come to light. It lingers briefly and then "shoots" the prey with the 2 long tentacles to hold it securely. The common squid then wraps its remaining tentacles around the prey or devours it immediately. The prey jump is used for larger crabs. The two long tentacles are not used for this type of prey capture. It would be too dangerous for the common squid if the other animal were able to injure its long tentacles. Here, too, the common octopus moves into a position in which it can see the prey well and then “jumps” onto the prey in order to then clasp it with its eight smaller tentacles. Then the shell of the prey is opened with a kind of sharp beak in the mouth of the Sepia, and a nerve poison then paralyzes it. Finally, the inside of the prey is liquefied and sucked out by enzymes in the saliva of the common squid Sepia. This can take up to an hour.
Distribution and occurrence
The common squid occurs from the very shallow subtidal to a depth of about 200 meters. Young animals do not go deeper than 50 to 80 m because their air-filled shell cannot withstand higher pressures. The common octopus occurs from the northern North Sea (up to about 63 degrees; southern Norwegian coastal region) over the west coasts of the British Isles, in the Mediterranean and on the west coast of North Africa up to about 15 degrees. The species is absent in the southern North Sea (English east coast, German and Dutch Wadden Sea coast).
literature
- Patrizia Jereb, Clyde FE Roper: Cephalopods of the World - An Annotated and Illustrated Catalog of Cephalopod Species Known to Date. Volume 1 Chambered Nautiluses and Sepioids (Nautilidae, Sepiidae, Sepiolidae, Sepiadariidae, Isiosepiidae and Spirulidae). FAO Species Catalog for Fishery Purposes, No. 4, 1: 1-262, Rome 2005, ISBN 92-5-105383-9
Web links
- Sepia officinalis inthe IUCN 2013 Red List of Threatened Species . Posted by: Barratt, I. & Allcock, L., 2009. Retrieved February 8, 2020. ( least concern )